woodbury



(No Model.)

J. A. WOODBURY, J. MERRILL, G. PATTEN & E. F. WOODBURY. HOT AIR ENGINE.

No. 327,748. T Patented Oct. 6, 1885.

Iupeniors modbury, Joshua/jl l'errill,

21/ lfi Jillorney.

Edward/E modbur w m a DNTTEE STATES PATENT OFFICE,

JAMES A. YVOODBURY, OF WINCHESTER, JOSHUA MERRILL, GEORGE PATTEN, ANDEDVARD F. \VOODBURY, OF BOSTON, MASS.

HOT-AIR ENGINE.

SPECIFICATION forming part of Letters Patent No, 327,748, iated October6, 1885.

Application filed January 523, 1885. Serial No. 153,777. (No model.)

T0 at whom it may concern.-

Be it known that we, JAMES A. XVOODBURY, of WVinchester, in the countyof Middlesex and State of Massachusetts, J OSHUA MERRILL,

GEORGE PATTEN, and EDWARD F. WooDBURY, of Boston, in the county ofSuffolk and State of Massachusetts, have invented, jointly, new anduseful Improvements in HotAir Engines, of which the following, taken inconnection with the accompanying drawing, is a speci tication.

Our invention relates to air-engines, and particularly to that class ofsuch engines in which air of greater density than common air is used andis alternately heated and cooled over and over again without exhaustingthe same; and it consists in a novel construc tion, arrangement, andcombination of the several parts which constitute the heater,regeneralor, and cooler, which will be readily understood by referenceto the description of the drawings, and to the claims, to be hereinaftergiven.

The accompanying drawing represents a central vertical section throughthe reverser cylinder, the heater, the cooler, and the regenerator of anair-engine embodying our invcntion.

In the drawing, D isa short cylinder, which is bolted to and supportedby the furnace casing, (not shown,) as described in another applicationof ours filed June 7, 1881, No. 35,137, of which this is a division. Tothe lower flange of the cylinder D is bolted the annular heater E, whichextends downward therefrom into the combustion chamber. (Not shown.)

G is the lower section of the reverser-cylinder supported by lugs d d,projecting from its upper end upon a shoulder formed in the innerperiphery of the cylinder D, near its upper end, said cylinder G havingan exterior diameter somewhat less than the interior diameter of thecylinder D and the outer wall of the heater E,and extending downwardinto the annular space between the outer and inner vertical walls of theheater, all in a wellknown manner.

To the upper end of the cylinder D is bolted the upper section, G, ofthe reverser-cyliner, closed at its upper end, and provided with anupwardly projecting central hub through a suitable opening, in whichworks the piston-rod T, to the lower end of which is attached the pistonU, the upper end of which k is provided with a packing-ring arranged towork airtight in the cylinder G.

V is the outer casing of the cooling-chamber provided with a base-flangewhich rests upon the flange of the cylinder G andis bolted with it tothe upper end of the cylinder D, said casing being made in the form ofan inverted cnp,with a small hole in the center of its upper end,through which the central hub of the cylinder G projects, said casing Vbeing firmly secured to said hub with a packed joint, thereby formingacoolingchamber, A, which surrounds and incloses the periphery of thereversercylinder G, within which the packing-ring of the piston U works,and the whole upper end of said cylinder G except the small areaoccupied by the central hub which forms the bearing of the pistourod T.

Two circular rows or series of thin copper pipes, at m, are arranged inthe ccolingchamher A, the lower ends of which are inserted through theflange of the reverser-cylinder G, and their upper ends have formedtherein semicircular bands and are inserted through openings in theupper end or head of said cylinder G so as to open into the interior ofthe reverser-cylinder directly above the upper end of the piston U, asshown.

I11 consequence of our arrangement of the cooling-chamber surroundingthe periphery of that portion of the reverser-cylinder which is abovethe piston U when it is in its lowest position, and nearly the entireupper end of said cylinder, we obtain a greatly-increased area ofcooling-surface upon the cylinder G itself, and we are also enabled tovery largely increase the area of pipecooling surface by inserting morepipes than can be used when the coolingchamber does not cover the upperend of the reverser-cylinder.

This is a very important feature of our invention, as the effectivenessof an air-engine depends almost entirely upon the rapidity with whichthe air can be alternately heated and cooled; and it has beendemonstrated that while there is comparatively little trouble eX-perienced in heating the air so long as the heater lasts or does notburn out, great difficulties have been experienced in cooling the airwith sufficient rapidity, which difficulties we claim to have overcomeby the construction of the cooler here shown and described.

Another very important factor in an airengine, as an aid in the rapidheating and coOling of the air, is the regenerator, a passage throughwhich the air passes from the heater to the cooling-chamber, and viceversa, and when the hot air gives off a considerable percentage of itsheat in passing from-the heating-chamber to the cooling-chamber andtakes it up again as it passes to the heatingchaniber again after havingbeen cooled in the cooling-chamber.

It has been demonstrated by actual OX1)81lment that copper plates in theregenerator are the most effective in extracting heat from and giving itoff to the air passing through said regenerator; but we have also foundby practical test that copper will not withstand the corroding ordisintegrating action of grate heat as well as iron, and hence we divideour regenerator'plates circnmferentially into two sections,and makethose plates 10 in thelower section or nearest to the lire ofiron,andthose in the upper section of copper. By this means we obtain themost effective result consistent with durability.

The upper end of the cylinder D is counter bored to form therein anexpansion of its inner periphery suflicient to allow both rows of thepipes m m to open into and communicate with the regenerator-chamber, asshown.

The water for cooling the air enters the eoolingchamber through the pipeZ, and after traversing the cooling-chamber is discharged therefromthrough the pipe. (Shown near the upper lefthand corner of the casingV.)

The cooler herein described and claimed is shown and described but notclaimed in the Letters Patent Nos. 289,484 and 289,485, granted to usDecember 4, 1883, the applications for which were filed May 16, 1883,and all of the features shown, described, and claimed in thisapplication originally formed a part of an application of ours filedJune 7, 1881, No. 35,137, of which this application is a division.

Vhat we claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. In an air-engine provided with an annular regenerator-chambersurrounding and inclosing the reverser-cylinder and extending to or intothe heater, two sets of regeneratorplates in said regenerator-chamber,the lower set made of iron and the upper set made of copper,substantially as and for the purposes described.

2. In an air-engine, a cooler-chamber surrounding and inclosing theperiphery of that portion of the reverser-cylinder in which the packingof the reversenpiston works and the whole upper end of saidrevcrser-cylinder except a central hub for a guide for the reverserpiston-rod, substantially as described.

3. The combination of the reversencylinder G, the water-chamber A,surrounding and inclosing the periphery and upper end of said cylinder,.and two rows of bent pipes, in in, having their lower ends insertedthrough the flange of the cylinder G and their upper ends insertedtl'irongh the head of said cylinder, substantially as described.

In testimony whereof we have signed our names to this specification, inthe presence of two subscribing witnesses, on this 13th day of January,A. D.1885. 7

JAMES A. VVOODBURY. JOSHUA MERRILL. GEORGE PATTEN. EDWARD F. \VOODBURY.

\Vitnesses:

N. C. LOMBARD, WALTER E. LOMBARD.

